Buoyant cover

ABSTRACT

A buoyant cover has a planar body, the body having a first buoyant insulating layer, a second tensile layer overlaying the first buoyant insulating layer, the planar body having a periphery configured based on the tank perimeter to provide a limited gap with the tank perimeter, and the body defining a plurality of peripheral holes positioned about the periphery and proximate the periphery. The second tensile layer may be wrapped about an edge of the first buoyant insulating layer. There may be an underlying portion of the second tensile layer near the periphery. A peripheral seam may be sewn through the underlying portion and the first buoyant insulating layer. The peripheral holes may penetrate the underlying portion. There may be grommets defining the peripheral holes. The planar body may have a circular periphery.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/964,767 filed on Jan. 23, 2020, entitled “FloatingCover System for Above Ground Tanks,” which is hereby incorporated byreference in its entirety for all that is taught and disclosed therein.

FIELD OF THE INVENTION

The present invention relates to open top outdoor fluid storage tanks,and more particularly to a buoyant cover that insulates open top outdoorfluid storage tanks to prevent fluid and heat loss.

BACKGROUND AND SUMMARY OF THE INVENTION

Buoyant covers are used to insulate open top outdoor fluid storage tanksto prevent fluid and heat loss. Many floating cover systems have beentried for Oil & Gas operations in order to reduce energy loss from opentop outdoor fluid storage tanks that expose water to the environment. Inmost cases, water used for fracking operations is heated. Heating thewater exponentially increases the amount of water and energy loss due toevaporative, conductive, convective, and radiative methods of energytransfer. Placing a floating cover on the surface of the water canreduce evaporative energy loss by 65% to 85% depending on conditions.

Because of the significant problems associated with water and energyloss, many types of floating covers have been tried, but all of themsuffer from being disrupted by high winds. High winds can disrupt thefloating cover by moving the cover within the tank to expose more of thewater's surface, lifting the cover out of the tank entirely, or causingwater to accumulate on top of the cover, eventually causing the cover tosink and expose the water's surface. High winds create negative pressureeddies above conventional floating covers that eventually lift thematerial. Not only is the water surface subsequently exposed, but theinsulating material conventional floating covers is made from isvulnerable to wind damage.

Therefore, a need exists for a new and improved buoyant cover that isresistant to being lifted and damaged by high winds. In this regard, thevarious embodiments of the present invention substantially fulfill atleast some of these needs. In this respect, the buoyant cover accordingto the present invention substantially departs from the conventionalconcepts and designs of the prior art, and in doing so provides anapparatus primarily developed for the purpose of providing a buoyantcover that is resistant to being lifted and damaged by high winds.

The present invention provides an improved buoyant cover, and overcomesthe above-mentioned disadvantages and drawbacks of the prior art. Assuch, the general purpose of the present invention, which will bedescribed subsequently in greater detail, is to provide an improvedbuoyant cover that has all the advantages of the prior art mentionedabove.

To attain this, the preferred embodiment of the present inventionessentially comprises a planar body, the body having a first buoyantinsulating layer, a second tensile layer overlaying the first buoyantinsulating layer, the planar body having a periphery configured based onthe tank perimeter to provide a limited gap with the tank perimeter, andthe body defining a plurality of peripheral holes positioned about theperiphery and proximate the periphery. The second tensile layer may bewrapped about an edge of the first buoyant insulating layer. There maybe an underlying portion of the second tensile layer near the periphery.A peripheral seam may be sewn through the underlying portion and thefirst buoyant insulating layer. The peripheral holes may penetrate theunderlying portion. There may be grommets defining the peripheral holes.The planar body may have a circular periphery. There are, of course,additional features of the invention that will be described hereinafterand which will form the subject matter of the claims attached.

There has thus been outlined, rather broadly, the more importantfeatures of the invention in order that the detailed description thereofthat follows may be better understood and in order that the presentcontribution to the art may be better appreciated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of the current embodiment of a buoyantcover constructed in accordance with the principles of the presentinvention in use attached to an open top outdoor fluid storage tank.

FIG. 2 is a side sectional fragmentary view of the buoyant cover of FIG.1 in use attached to an open top outdoor fluid storage tank with thewater at a high level.

FIG. 3 is a side sectional fragmentary view of the buoyant cover of FIG.1 in use attached to an open top outdoor fluid storage tank with thewater at a low level relative to FIG. 2.

FIG. 4 is a top view of one-half of the first buoyant insulating layerof the buoyant cover of FIG. 1.

FIG. 5 is a side sectional fragmentary view of the buoyant cover of FIG.1 in use with the two halves of the buoyant cover releasably connectedto one another.

FIG. 6 is a top isometric view one-half of the buoyant cover of FIG. 1rolled up on a core to facilitate transportation and storage.

The same reference numerals refer to the same parts throughout thevarious figures.

DESCRIPTION OF THE CURRENT EMBODIMENT

An embodiment of the buoyant cover of the present invention is shown andgenerally designated by the reference numeral 10.

FIG. 1 illustrates the improved buoyant cover 10 of the presentinvention. More particularly, FIG. 1 shows the buoyant cover in useattached to an open top outdoor fluid storage tank 12 having a tankperimeter 14 containing heated water 16. The buoyant cover is a planarbody formed in multiple parts (halves 18, 20) in the current embodimentto have a periphery 22 configured based on the tank perimeter to providea limited gap with the tank perimeter. In the current embodiment, theperiphery is circular. The two halves are mirror images of one anotherand are each semi-circular in shape. Each half has a first buoyantinsulating layer 24 and a second tensile layer 26 overlaying the firstbuoyant insulating layer. Each half defines a plurality of peripheralholes 28 positioned about the periphery and proximate the periphery. Aplurality of vertical lines 30 each has an upper end 32 configured toconnect to an upper portion of the tank 34 and an intermediate portion36 passing through a respective one of the peripheral holes. A weight38, which is a sandbag in the current embodiment, is connected to alower end 40 of each line to place each line in tension to retain theperiphery of the buoyant cover adjacent to the tank perimeter. In thecurrent embodiment, the open top outdoor fluid storage tank has a heightof 12 feet and a diameter of 135 feet. However, the buoyant cover can bemade in any desired size to fit a corresponding open top outdoor fluidstorage tank, which typically have a diameter in the range of 70 feet to195 feet.

FIGS. 2 & 3 illustrate the improved buoyant cover 10 of the presentinvention. More particularly, FIG. 2 shows the buoyant cover in anelevated position with the heated water 16 at a high level within theopen top outdoor fluid storage tank 12. FIG. 3 shows the buoyant coverin an elevated position with the heated water 16 at a lower level withinthe open top outdoor fluid storage tank 12 relative to FIG. 2. Theplurality of vertical lines 30 received in the peripheral holes 28 allowthe buoyant cover to rise and fall in response to changes of the amountof heated water in the open top outdoor fluid storage tank 12. The waterlevel continually changes during the fracking process. The lines beingplaced in tension by the weights 38 ensures the buoyant cover can onlymove in a vertical direction with respect to the tank perimeter. Thismovement limitation prevents the buoyant cover from being displaced bywind, flipped over, or being sunk by water accumulation from windblownexposed water. The second tensile layer 26 also increases the windresistance of the buoyant cover by reducing the negative pressure thatwind would otherwise create on the first buoyant insulating layer 24. Inthe current embodiment, the second tensile layer is a woven mesh ofmaterial manufactured by Wind Defender, LLC of Pottsville, Pa. Thesecond tensile layer is a geotextile windscreen made of knitted, green,UV stabilized high density polyethylene (HDPE) filament. Use of thesecond tensile layer material to reduce negative pressure buildup andsubsequent wind damage to a high-density polyethylene liner customarilyused in landfills has been proven. Testing of the buoyant cover on sitein a remote area of Colorado established the buoyant cover maintainedits desired position covering the heated water despite being subjectedto wind speeds exceeding 60 mph.

FIG. 4 illustrates the improved first buoyant insulating layer 24 of thepresent invention. More particularly, FIG. 4 shows how each half 18, 20of the first buoyant insulating layer of the buoyant cover 10 is formedfrom a plurality of strips of material 40. The first buoyant insulatinglayer is a ⅛-inch-thick foam sheet 42 made of polyethylene foammanufactured by ProtecPac of Sidney, Ohio that has been laminated onboth sides with woven coated polyethylene upper and lower sheets 44, 46manufactured by Intertape Polymer Group, Inc. of Sarasota, Fla. Theupper and lower sheets are HDPE tapes that are then coated with a 1.5mil blue upper layer and a 1.5 mil white lower layer. The totalthickness of the polyethylene upper and lower sheets is around 3-4 milon each side of the foam. The foam is a closed cell-foam sheet to nottake on any water during usage. The strips of material are acquiredhaving a 6-foot width. Each strip of material is welded to adjacentstrips of material with a heated wedge welder. Once the strips ofmaterial are welded together, the periphery is trimmed in a semicircularshape to fit the tank perimeter 14 so that the first buoyant insulatinglayer will fit within the open top outdoor fluid storage tank and floatfreely while covering the surface of the heated water 16. Depending oncustomer request, about 95-99% of the surface of the heated water iscovered by the two halves of the first buoyant insulating layer.

FIG. 5 illustrates the improved buoyant cover 10 of the presentinvention. More particularly, FIG. 5 shows the two halves 18, 20 of thebuoyant cover connected by fasteners 48, which are carabiners in thecurrent embodiment. The second tensile layer 26 is manufactured in20-foot-wide sheets that are sewn together to match the shape of eachhalf of the first buoyant insulating layer 24 while being slightlylarger. The increased size of the second tensile layer 26 of each halfof the buoyant cover relative to each half of the first buoyantinsulating layer enables the second tensile layer to be wrapped about anedge 50 of the first buoyant insulating layer 24 to encapsulate theentire top surface 52 of the first buoyant insulating layer. Thewrapping results in an underlying portion 54 of the second tensile layernear the periphery 22 that extends 6-inch underneath in the currentembodiment. A peripheral seam 56 is sewn through the underlying portionand the first buoyant insulating layer to secure the second tensilelayer to the first buoyant insulating layer. The peripheral holes 28penetrate the underlying portion and are defined by #2-#3 grommets 58 inthe current embodiment to prevent tearing. The two halves of the buoyantcover are joined at a seam 60 with peripheral holes aligned withrespective peripheral holes in an adjacent half, and the fastenersconnected to each peripheral hole of a corresponding pair of peripheralholes. In the current embodiment, the peripheral holes are spaced every4 feet along the seam and every 6 feet along the semicircular-shapedportion of the periphery.

FIG. 6 illustrates the improved buoyant cover 10 of the presentinvention. More particularly, FIG. 6 shows how each of the two halves18, 20 of the buoyant cover can be rolled up on a core 62 to facilitatetransport and storage. To use the buoyant cover, the two halves areunrolled and then unfolded. Subsequently, the two halves are connectedtogether at the seam 60 with the fasteners 48, and the vertical lines 30with connected weights 38 are passed through the peripheral holes 28.The open top outdoor fluid storage tank 12 is then constructed aroundthe buoyant cover, and the upper ends 32 of the lines are connected tothe upper portion of the tank 34. Finally, the tank is filled withheated water 16 underneath the buoyant cover, and the buoyant coverrises up the lines with the water level while covering the heated water.

While a current embodiment of a buoyant cover has been described indetail, it should be apparent that modifications and variations theretoare possible, all of which fall within the true spirit and scope of theinvention. With respect to the above description then, it is to berealized that the optimum dimensional relationships for the parts of theinvention, to include variations in size, materials, shape, form,function and manner of operation, assembly and use, are deemed readilyapparent and obvious to one skilled in the art, and all equivalentrelationships to those illustrated in the drawings and described in thespecification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described, and accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

I claim:
 1. A buoyant cover for an open top outdoor fluid storage tankhaving a tank perimeter comprising: a planar body; the planar bodyhaving a first buoyant insulating layer; a second tensile layeroverlaying the first buoyant insulating layer; the body having aperiphery configured based on the tank perimeter to provide a limitedgap with the tank perimeter; and the planar body defining a plurality ofperipheral holes positioned about the periphery and proximate theperiphery.
 2. The buoyant cover of claim 1 wherein the second tensilelayer is wrapped about an edge of the first buoyant insulating layer. 3.The buoyant cover of claim 2 including an underlying portion of thesecond tensile layer near the periphery.
 4. The buoyant cover of claim 3wherein a peripheral seam is sewn through the underlying portion and thefirst buoyant insulating layer.
 5. The buoyant cover of claim 3 whereinthe peripheral holes penetrate the underlying portion.
 6. The buoyantcover of claim 1 including grommets defining the peripheral holes. 7.The buoyant cover of claim 1 wherein the planar body has a circularperiphery.
 8. The buoyant cover of claim 1 wherein the planar body isformed in multiple parts, each having holes about their peripheries andjoined at a seam with peripheral holes aligned with respectiveperipheral holes in an adjacent part, and fasteners connected to eachperipheral hole of a corresponding pair of peripheral holes.
 9. Thebuoyant cover of claim 1 wherein the first buoyant insulating layer is aclosed-cell foam sheet between laminated upper and lower sheets.
 10. Thebuoyant cover of claim 9 wherein the laminated sheets are polyethylene.11. The buoyant cover of claim 1 wherein the second tensile layer is awoven mesh.
 12. The buoyant cover of claim 1 including a plurality ofvertical lines each having an upper end configured to connect to anupper portion of the tank, and an intermediate portion passing through arespective one of the peripheral holes.
 13. The buoyant cover of claim12 including a weight connected to a lower end of each line.
 14. Thebuoyant cover of claim 12 wherein the length of each line is based onthe height of the tank.